Improvement in iievelling-staff



` To alhwhom "it mq/y concern:`

anni sin,

WILLIAM H. ROBINSON, or VERMONT, ILLINOIS.v i ""Lezars'rom No. 90,025,mamy 11,1869. i

IMPROVEMENT m LEvELLrNG-s'rarr.

V The Schedule referred to in theseiLettei-s Patent and making part ofthe same. ,y

1Be `it Yknown that I, WILLIAM H.'RoB1NsoN,'of

Vermont, in the `county of Fulton, and State of Illinois, have inventeda new and valuable Improvement in Levelling-Rods, (device `forcross-sectioning earthworkg) `and I do hereby declare that thefollowingis a full, clear, and exact description of the construction andoperation of the same, reference being had to' the annexed drawings,making apart of this specication, and tothe letters and figures ofreference marked thereon. Y l

Figure 1,0f the drawings, is a representation of the rod, `s lowing theface and' the side, which is used as anY or inary levelling-rod. v

Figure 2 is a representation of the rod, showing the backand the side,opposite the oneused in ordinary levelling. y i ,4 y

Figure `3, a pulley, one of which is attached 'to each end of the rod. r

My mode of constructing the rod is as follows:

I` take a straight rod of light wood, aboutone 4and a quarter nchthick,two inches wide,`and twelveA feet long, and,v in order to make it aslight as possible without diminishing the ,-widtb, I make it hollow. f

A'pulley,.fig. 3, is attached to each end of the rod'. A band ofleather, or some other flexible non-elastic material, of thesame widthas andtwicethe length of the rod, isl passed over the pulleys, drawnperfectly tight, and the ends fastened rmly and smoothl y1 together,forming the face and back of the rod.

It istben painted white, and graduated into feet )and tenths of afoot.AV l Thegraduations on the fixed part of the rod, are numbered in acontinuousseries, from the bottomup the side, (see iig. 1,) thence; downthe-opposite side, (see iig. 2,) to the bottom. 1

The graduations on the movable part or band, are

numbered both ways, one series running from` the Zero or target down theface to `the bottom, (see fig. 1;) `thence up the back, (see iig. 2,) tothe top; thence o down the face again, (see Iig. 1,) to the place ofbeginning. y

VThe `other series runs up Ithe rod, on the face, to the top, (see fig.1;) thence down the back, (see fig. 2,)

Ato the-bottom; thence up the face, (see fig. 1,) to the` place ofbeginning, as before.`

` l The figure on the fixed part of therod, (see righthand ,sides offigs. 1 and 2,) representing tenths, are

painted black, and thoserepresentin'g feet are painted red. 3 v

The iigures on the bandy are also painted-'black and red, but the blackfigures represent tenths from the target, both ways, to twelve feet, orhalf the length v of the band,while the red ones represent feet, andfrom thence, around to the targetagaimthe black iigures represent feetand thegred ones tenths.

The manuel-.of using the rod is as follows:

Ascertain, by using the rod as an ordinary levelling rod, the height ofthe instrument, (the common engineers level,) above or below the givengrade at the station where the observations'are to be made, and set thetarget or 'zero accordingly.

The'nnmberon the face of the rod which coincides with the line ofeollimation of the instrument, is then the cut or fill, as the case maybe, at that station.

, If the number is` below' the target, it represents a cut, and if -itisabove the target, it represents a fill.

If the instrument is morev than twelve feet, or the length of the rodabove grade, the target should be set by the figures on the side of therod, opposite to the side used in ordinaryT levelling.' (See right-handside of iig. 2.) Itshould lbe on the bank of the rod. y

The above rule is somewhat xnollied by the following, which the operatorshould be careful ,to remember: When the target is on the face of therod, the black son ofthe instrument being more than twelve feet, or

thelength of the rodl above grade, the numbers run l ningvfrom the topof thel rod downward, are the only ones noticed, and they invariablyrepresent a cut.

When the target is on the back of th-rod, by reason ofthe instrumentbeing below grade, the numbers running from the bottom of the rodupwards, are the' only ones noticed, and they invariably represent afill.

1fv the instrument is more than the` length of the rod below, or morethan twice the length of the rod above grade, the target may be set onthe back of the rod, ten, twenty, or thirty feet,- as the case may be,less above or'below grade than the calculations show that it should beset, and the ten, twenty, or thirtyv `added to the numbersread from therod.

What I claim as my invention, and desire to secure by Letters Patent, is

-A levelling-rod, having a travelling-band, as de-i scribed, movingaround the same longitudinally, when `4 said rod and band"`a.regraduated and operate substantially as and for thepurposes specified.

In testimony thatfI claim the above, vI have hereunto subscribed myname, in'the presence of two witnesses.

`WILLIAM n. ROBINsoN.

Witnesses: Y

BALLARDHOBART, i

BENJAMIN ARMITAGE HATTERSLEY.

@anni ire.

iignres are the only ones noticed as representing the i

